The principle objectives of the several components of this program include a) Qualitative and quantitative histofluorescence of central monoaminergic systems involved in neuroendocrine processes; b) Development of in vitro organ-culture and dispersed-cell preparations of ependyma of median eminence, pinealocytes of the pineal gland, neurones of specific hypothalamic nuclei, and adenohypophyseal cells of the pituary gland; c) Transmission and scanning electron microscopy of the circumventricular organs of rat and other mammalian brains; d) Studies on the role of the ventricular CSF in neuroendocrine processes.